19-1185; Rev 2; 5/97 General Description The MAX2601/MAX2602 are RF power transistors opti- mized for use in portable cellular and wireless equipment that operates from three NiCd/NiMH cells or on Li-lon cell. These transistors deliver 1W of RF power from a 3.6V supply with efficiency of 58% when biased for con- stant-envelope applications (e.g., FM or FSK). For NADC (1S-54) operation, they deliver 29cm with -28dBc ACPR from a 4.8V supply. The MAX2601 is a high-performance silicon bipolar RF power transistor. The MAX2602 includes a high- performance silicon bipolar RF power transistor, and a biasing diode that matches the thermal and process characteristics of the power transistor. This diode is used to create a bias network that accurately controls the power transistor's collector current as the tempera- ture changes. The MAX2601/MAX2602 can be used as the final stage in a discrete or module power amplifier. Silicon bipolar technology eliminates the need for voltage inverters and sequencing circuitry, as required by GaAsFET power amplifiers. Furthermore, a drain switch is not required to turn off the MAX2601/MAX2602. This increases operating time in two ways: it allows lower system end-of-life battery voltage, and it eliminates the wasted power from a drain-switch device. The MAX2601/MAX2602 are available in thermally enhanced, 8-pin SO packages, which are screened to the extended temperature range (-40C to +85C). The MAX2602 is also available in die form. Applications Narrow-Band PCS (NPCS) 915MHz ISM Transmitters Microcellular GSM (Power Class 5) AMPS Cellular Phones Digital Cellular Phones Two-Way Paging CDPD Modems Land Mobile Radios Typical Application Circult appears at end of data sheet. PMAAXLIA MAK 3.6V, 1W RF Power Transistors for 900MHz Applications Features Low Voltage: Operates from 1 Li-ion or 3 NiCd/NiMH Batteries # DC-to-Microwave Operating Range # 1W Output Power at S00MHz * On-Chip Diode for Accurate Biasing (MAX2602) # Low-Cost Silicon Bipolar Technology # Does Not Require Negative Bias or Supply Switch # High Efficiency: 58% Ordering information PART TEMP. RANGE PIN-PACKAGE MAX2601ESA -40C to +85C 8 PSOPII MAX2602ESA -40C to +85C 8 PSOPII MAX2602E/D ~40C to +86C Dice* Dice are specified at Ta = +25C, DC parameters only. Pin Configurations TOP VIEW fH MAXIM je oo MAXIM Ae e [2 @ om Le elie E all re] eas Gf} U ale 8 [4 rs]8 8 [4] 5] 8 MAX2601 MAX2602 PSOPII PSOPII Maxim Integrated Products 10-49 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 408-737-7600 ext. 3468. 3 ND 9 mk, ; N o> 8MAX2601/MAX2602 3.6V, 1W RF Power Transistors for 900MHz Applications ABSOLUTE MAXIMUM RATINGS Collector-Emitter Voltage, Shorted Base (VCES)......ccccee Emitter Base Reverse Voltage (VEBOQ)......-.... 2, BIAS Diode Reverse Breakdown Voltage (MAX2602) ......... Average Collector Current (IC). ccccccecssceseseseerereres Continuous Power Dissipation (Ta = +70C) PSOPH (derate 8OmMW/C above +70C) (Note 1).......... 6.4W Note 1: Backside sitig must be properly soldered to ground plane (see Slug Layout Techniques section). Operating Temperature Range Storage Temperature Range. Junction Temperature Lead Temperature (soldering, 10sec) Stresses beyond those listed under Absoiute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these er any other conditions beyond those indicated in the operational! sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. DC ELECTRICAL CHARACTERISTICS (Ta = TIN to Tmax, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN Typ MAX | UNITS Emi BV Open ba! 1 Collector-Emitter Breakdown CEO ic < 100uA pen base V Voltage BVcES Shorted base 15 Collector-Emitter Sustaining _ Voltage LVceo $| ic = 200mA 5.0 i] Collector-Base Breakdown . Voltage BVcsBo | Ic < 100uA, emitter open 15 Vv DC Current Gain hee Ic = 250mA, Vce = 3V 100 Collector Cutoff Currant ICES Vce = 6V, Veg = OV 0.05 15 yA Output Capacitance Cos Ves = 3V, le = OmA, f = 1MHz 9.6 pF AC ELECTRICAL CHARACTERISTICS (Test Circuit of Figure 1, Voc = 3.6V, Veg = 0.750V, Z_oaD = ZSOURCE = 502, Pout = 30dBm, f = 836MHz, Ta = +25C, unless ath- erwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX | UNITS Frequency Range f (Note 2} pC 1 GHz Base Current lp 42 mA Vec = 3.6V, Pout = 30dBm -43 H i 2fo, 3fo dB amonics Voc = 3.0V, Pout = 29dBm a2 Power Gain Pout = 30dBm 11.6 dB Collector Efficiency n No modulation 58 % Stability under Continuous _ : Load Mismatch Conditions Vswr Voc = 5.5V, all angles (Note 3) a1 IM3 Pout = +30d8m total power, f1 = 835MHz, -16 Two-Tone IMR IME (2 = B36MHz 35 dBc Noise Figure NF Vep = 0.9V 3.3 dB Note 2: Guaranteed by design. Note 3: Under these conditions: a) no spurious oscillations shall be observed at collector greater than -60dBc; b) no parametric degradation is observable when mismatch is removed; and c) no current draw in excess of the package dissipation capability is observed. 10-50 MAAXLMA3.6V, 1W RF Power Transistors for 900MHz Applications Typical Operating Characteristics = (Test Circuit of Figure 1, input/output matching networks optimized for specific measurement frequency, Vcc = 3.6V, Vee = 0.750V, Pout = 30dBm, ZLoao = ZsouRCcE = 50Q, f = 836MHz, Ta = +25C. unless otherwise noted.) > TWO-TONE OUTPUT POWER AND [M3 TWO-TONE OUTPUT POWER, IM3, IM5 a COLLECTOR CURRENT vs. COLLECTOR CURRENT vs. INPUT POWER ND 10 = 3 35 Z Pout, IMB, AND INS | 5 Pour o 3 ARE RMS COMPOSITE 5 ARE RMS COMPOSTE out 9S TWO-TONE POWER LEVELS 08 A" = 1.00 0 Pour _ a ueves wl, = _, 06 4 Vpn = 0.954 E "1 = 2 = | & 2 2 ve-oov] 3 g * 4 ye 3g < 1 Ns = bee 7 . fe NN - 28 i 5 NO 02 Vag = 0.85V Cnn oO Vag = 0.80V eS 0 2 5 o 1 2 40064 5 6 04 05 06 07 08 5 10 5 20 8 N Vee (V) lee (A) INPUT POWER (dBm) TWO-TONE OUTPUT POWER, IMS, IMS ACPR vs. OUTPUT POWER COLLECTOR EFFICIENCY vs. OUTPUT POWER vs. INPUT POWER (f = 433Mltz) (IS-54 7/4 DOPSK MODULATION, Vyq = 0.85V) {1S-S4 /4 DOPSK MODULATION, Vax = 0.85V) 35 -20 60 P, Pour, (M3, AND IM5 _ % 30 gq LAREAMS COMPosiTE s -24 TWO-TONE POWER = 26 = PS s0v S 13, AND IMB Na S - = g AMS COMPOSITE S 5 2 15 F TWO-TONE & -30 & x = POWER LEVELS ZS a9 = a 34 20 5 36 10 38 4 -40 0 5 10 15 20 5 10 15 20 25 30 6 10 15 20 5 30 35 INPUT POWER (dBm) OUTPUT POWER (dBm) OUTPUT POWER (dBm) Pin Description PIN NAME FUNCTION MAX2601 MAX2602 1,8 1,8 Transistor Collector 2,3, 6, 7, Slug 2, 6, 7, Slug E Transistor Emitter Anode of the Biasing Diode that matches the thermal and process char- acteristics of ine power transistor. Requires a high-RF-impedance, low- _ 3 BIAS DC-impedance (e.g., inductor) connection to the transistor base (Pin 4). Current through the biasing diode (into Pin 3) is proportional to 1/15 the collector current in the transistor. 4,5 4,5 B Transistor Base PAAXIAA 10-54MAX2601/MAX2602 3.6V, 1W RF Power Transistors for 900MHz Applications Li = COILCRAFT AQST INDUCTOR, 18.5nH TH, T2= 1, 5022 TRANSMISSION LINE ON FR-4 Ves Figure 1. Test Circuit Detailed Description MAX2601/MAX2602 The MAX2601/MAX2602 are high-performance silicon bipolar transistors in power-enhanced, 8-pin SO pack- ages. The base and collector connections use two pins each to reduce series inductance. The emitter con- nects to three (MAX2602) or four (MAX2601) pins in addition to a back-side heat slug, which solders direct- ly to the PC board ground to reduce emitter inductance and improve thermal dissipation. The transistors are intended to be used in the common-emitter configura- tion for maximum power gain and power-added efficiency. Current Mirror Bias ({MAX2602 only) The MAX2602 includes a high-performance silicon bipolar RF power transistor and a thermally matched biasing diode that matches the power transistors ther- mal and process characteristics. This diode is used to create a bias network that accurately controls the power transistor's collector current as the temperature changes (Figure 2). The biasing diode is a scaled version of the power tran- sistors base-emitter junction, in such a way that the current through the biasing diode is 1/15 the quiescent collector current of the RF power transistor. Supplying the biasing diode with a constant current source and connecting the diades anode to the RF power transis- tor's base ensures that the RF power transistors quies- cent collector current remains constant through 10-52 Veo Vee f RFout Cour RFin it Figure 2. Bias Diode Application temperature variations. Simply tying the biasing diode to the supply through a resistor is adequate in most sit- uations. If large supply variations are anticipated, con- nect the biasing diode to a reference voltage through a resistor, or use a stable current source. Connect the biasing diode to the base of the RF power transistor through a large RF impedance, such as an RF choke (inductor), and decouple to ground through a surface- mount chip capacitor larger than 1000pF. MAAXIAA3.6V, 1W RF Power Transistors Applications Information Optimum Port impedance The source and load impedances presented to the MAX2601/MAX2602 have a direct impact upon its gain, output power, and linearity. Proper source- and load- terminating impedances (Zs and Zi) presented to the power transistor base and collector will ensure optimum performance. For a power transistor, simply applying the conjugate of the transistors input and output impedances calculated from small-signal S-parameters will yield less than opti- mur device performance. For maximum efficiency at Vag = 0.75V and Vcc = 3.6V, the optimum power-transistor source and load impedances (as defined in Figure 3) are: At 836MHz: Zs = 5.5 + j2.0 Z. = 6.54 )15 At433MHz: ZS = 9.5-j2.5 ZL = 8.5- jis Zs and Z|. reflect the impedances that should be pre- sented to the transistor's base and collector. The pack- age parasitics are dominated by inductance (as shown in Figure 3), and need to be accounted for when calcu- lating Zs and ZL. The internal bond and package inductances shown in Figure 3 should be included as part of the end- application matching network, depending upon exact layout topology. MAAXLMA for 900MHz Applications Slug Layout Techniques The most important connection to make to the MAX2601/MAX2602 is the back side. It should connect directly to the PC board ground plane if it is on the top side, or through numerous plated through-holes if the ground plane is buried. For maximum gain, this con- nection should have very little self-inductance. Since it is also the thermal path for heat dissipation, it must have low thermal impedance, and the ground plane should be large. AA 2.8nH LPL il Led Figure 3. Optimum Port impedance 10-53 = x 8 > : 8